Anyone subject to the disguised remuneration loan charge that hasn't yet filed a tax return or sorted a payment agreement with HMRC has until 30 September.
HMRC could issue fines of at least £100 to almost one million taxpayers who failed to file their self-assessment tax return by the 31 January deadline. Which? explains the penalties for delaying any further and excuses you could use to appeal.
Which? provides useful tips to file your tax return by midnight and avoid paying a penalty.
Find out whether you need to file a 2018-19 self-assessment tax return to declare child benefit payments - even if you don't usually need to submit one
Which? explains why pension savers might need to complete a self-assessment tax return and tips on what to watch out for to get it right.
Find out what self-assessment tax rules you need to know to ensure you make the most of this year's expenses and allowances for self-employed workers.
With the self-assessment deadline looming, scammers are ready to target unwitting taxpayers by impersonating HMRC in a variety of ways. Here's how to spot them.
Which?'s top tips on how to file your self-assessment tax return by the 31 January deadline and avoid a £100 fine from HMRC
Preparing your tax return? Here's our top tips on how to avoid overpaying your tax, explain which documents you'll need and the allowances you could claim.
Exclusive Which? research has found more than three in 10 people don't know which expenses can be claimed on their self-assessment tax return.